as·​tro·​labe | \ ˈa-strə-ˌlāb How to pronounce astrolabe (audio) also -ˌlab\

Definition of astrolabe

: a compact instrument used to observe and calculate the position of celestial bodies before the invention of the sextant

Illustration of astrolabe

Illustration of astrolabe

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The Astrolabe and the Stars

"Thyn Astrolabie hath a ring to putten on the thombe of thi right hond in taking the height of thinges." Thus begins a description of the astrolabe in A Treatise on the Astrolabe, a medieval user's guide penned by an amateur astronomer by the name of Geoffrey Chaucer. Chaucer is best known for his Middle English poetic masterpiece The Canterbury Tales, but when his nose wasn't buried in his writing, Chaucer was stargazing, and some of his passion for the heavens rubbed off on his son Lewis, who had displayed a special "abilite to lerne sciences touching nombres and proporciouns." Chaucer dedicated his treatise to the 10-year-old boy, setting his instructions not in the usual Latin, but in "naked wordes in Englissh" so that little Lewis could understand. When he got older, Lewis may have learned that the word astrolabe traces to the Greek name for the instrument.

Examples of astrolabe in a Sentence

Recent Examples on the Web

There also appears to be new imagery shown in the metallic astrolabe or armilla that hangs above the map. Erica Gonzales, Harper's BAZAAR, "The Game of Thrones Season 8 Title Sequence Is Completely Different," 15 Apr. 2019 One is an astrolabe, an instrument used to measure the position of stars. Kamasi Washington, WSJ, "Jazz Musician Kamasi Washington’s Favorite Things," 8 Jan. 2019 Without magnetic compasses or tools like astrolabes, the Vikings likely relied on primitive solar compasses to navigate, which uses the position of the sun to determine north. Jason Daley, Smithsonian, "Simulation Suggests Viking Sunstones of Legend Could Have Worked," 9 Apr. 2018 By aligning an astrolabe perpendicular to the horizon, ancient astronomers could calculate measurements like time and position. David Mearns, National Geographic, "Rare Solar Navigation Tool Found in Ancient Shipwreck," 24 Oct. 2017 Accurate instruments, such as the astrolabe, allowed people to measure the motion of the planets and thus predict movements in the heavens, particularly phenomena like solar and lunar eclipses and the motions of planets like Venus. Carla J. Mulford, Smithsonian, "Benjamin Franklin Mocked Eclipse Astrology to Elevate Science," 10 Aug. 2017 Mariner’s astrolabes came into use much later, during the late 15th century. Brigit Katz, Smithsonian, "Rare Mariner’s Astrolabe Found in Shipwreck Near Oman," 27 Oct. 2017 Astrolabes used by early sea explorers are frequently referred to as mariner's astrolabes. David Mearns, National Geographic, "Rare Solar Navigation Tool Found in Ancient Shipwreck," 24 Oct. 2017 Three astrolabes, devices used for navigation, should be flown to Portugal for restoration and research, Noli said. Washington Post, "In Namibia, 1533 Portuguese shipwreck’s relics hidden away," 15 Sep. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'astrolabe.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of astrolabe

14th century, in the meaning defined above

History and Etymology for astrolabe

Middle English, from Anglo-French & Medieval Latin; Anglo-French astrelabe, from Medieval Latin astrolabium, from Late Greek astrolabion, from Greek astrolabos, from astr- + lambanein to take — more at latch

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Last Updated

17 Sep 2019

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Time Traveler for astrolabe

The first known use of astrolabe was in the 14th century

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